From what I have heard, B&B (Barker) was a seperate company until bought out by Stelling & Hellings.

'California' Bill Fisher talks about these in his speed manual.

They increase the rocker ratio from 1.5 to 1.7 yielding an increase in lift of .065. They replace just the intake rockers and while they don't change the advertised duration of your cam . . . they do increase its intake duration at .050.

They were advertised to increase output by 5 horse power on a stock 216. California Bill used them on every one of his 216 dyno-test builds - no matter how wild the cam was to begin with.

They will cause the pushrods to be at an angle, and would probably need the pushrod holes in the head to be massaged for clearance. It was my understanding that they were 1.6 ratio, but I could be remembering wrong. It should say in the instructions.

Is any one using these Hi-lift rockers on their engine? What kind of performance gains have you noticed with them? Besides the push rod / head clearance issue are there any other problems running these Hi-lift rockers?

Thanks for the heads up gearhead/jimfred . . . I will watch the pushrod hole clearances closely when I do my build. Perhaps I may even try fit & run them on the stock setup before I tear it down.

As for the instructions, they pretty much say "slap em in, set the lash and go"

Up until I read jimfred's reply on this thread I had never heard of clearance or bending problems with higher than stock ratio rockers. But I am new to wrenching on Sixes.

When I was younger we played with V8s and this was just another variable. In fact I have read several tech articles that suggest that a balance of increased rocker ratio and lobe lift is easier on the valve train than increasing only lobe lift: http://www.pontiacstreetperformance.com/psp/RockerArms.html

The other thing that I am curious about is just how tight are the pushrod holes in an inliner? Based on my measurements these rockers don't move the top of push rod very far at all.

The distance from the fulcrum to the valve stem is roughly 2.1". The stock rocker ratio is 1.5. So the distance from the fulcrum to push rod is roughly 1.4".

Well I measured the Barker's this morning:

Of course Barker can't vary the distance to valve stem -- so it is roughly stock. But the distance to the push rod is indeed shorter as we would expect in order to acheive the higher ratio

2.1" divided by a rocker ratio of 1.7 = 1.235". Which is a difference of .16" and with a rougly 11" push rod we are moving it about .88 degrees off perpendicular. Doesn't seem like enough to create a risk of bending the rod. Yet now that I think about it .16 is the better part of three pennies . . . perhaps I will need to do some grinding.

For those who have never seen these before, there are some more pics below . . .

I actually have a set on Ebay right now. I dont know the rules of this forum so I won't post a link, but just do a search. I actually have 2 NOS sets of these and was going to put them on my 235, but found out they won't work. However, I do have a set of Thomas adjustable magnesium rocker arms for 235/261's. Has anyone ever heard of them? I hate to use them because Magnesium gets so brittle, but they're kinda neat and SUPER light!Chad

if you have a 58-62 block, you should use 58-62 rocker arms, or the amount of oil going to the top end may be affected. The oil groove size in the arms was changed when they went from the oil line system ('57-earlier) to the drilled block system 58-62.

hey, i am a custom bike builder, who just picked up a 64 impala, 230 I6. now i use corrected ratio rocker arms on my bikes all the time. because i will find a nice steep ramp slope, and suitable duration to put me in the torque band i am looking for, but if i want to step up in cam size, all that goes away... a higher duration usualy means wider more gradual ramps, killing my bottom end...so with the 1.7 rockers i get the bennifet of the steep ramps ultimatly narrower durration, but the benafit of the higher lift.....which will slightly affect durration, but rarely noticeable...so now calculate the real difference between your mechanical, and your corrected compression ratio, by measuring dome, squish, and compressed gasket height, as well as knowing your valve overlap...so as u can see i am all for high lift rockers..however on the bikes, to keep from any power loss due to heat and friction,as well as push rod flexing. i use taperlites..which reduce in outer diameter, from 7/16. to 3/8 .so all stress nstays within the rod itself. its not a uniform shape that can bend or disfigure... so does anyone know if they make anything like taperlites for auto use...just a suggestion...let me know............bareknuckle...

These were on e-bay a few weeks back (Barker) & a lot of money as I recall.

These worked good back in the 50s & many used them cause it was easy to put them on, instead of changing the cam. The push rods would rub a little as Bryan mentioned but not 'bend' and they weren't "roller" rockers, just 'hi lift'.

There okay for stock but N/G with a 'cam' as the lift is to much & can cause the valve spring to collapse completly.

They were part of the "Hot Rod package" many did.Milled head (.125), high lift rockers, 2 carb & headers with a hot coil too.

It would make a 85Hp 216" engine 140+/- and made money for the Accessory Houses plus a lot of noise.

On the Buick str 8 I screwed a bolt in to the adjustment hole on the rocker arm- milled it flat-made a fixture with a guide hole in it and redrilled the adjustment screw hole closer to the rocker shaft. I did have a clearance problem with the push rod-cured by using the same die grinder I ported the head with I ground the clearance I needeed . The problem was at the top of the hole 1'-1.5' down. Buicks had tubular pushrods and I never bend any at 6000 RPM. Is there anybody else out there that would like to build an engine the way we used to without all the technoligy we have today- just to see if it still works??? 1 OL REDNECK.

That works on anything with enough area between the adjuster hole and the center shaft tunnel area.Sometimes you get either more ratio, or more safety margin (or both) by reducing the adjuster thread size, but match the ball diameter to your original or you'll need new pushrods.The new ratio has to be a substantial change to justify the work (not to mention using up the rockers!).Example only: the distance from the shaft center to the pushrod adjuster ball center is 1-11/32" (1.34375"). and that from the shaft to the pad radius center is 2", the ratio is 2 ÷ 1.34375, or 1.488:1. Lift with a .280" lobe is .417"Moving the adjuster 1/8" closer makes the ratio 2 ÷ 1.28125, or 1.64:1. This adds about .042" to the lift.

I have 2 sets of NOS Thomas Magnesium rockers for a GMC but have never used them on any of my race engines. They were for both intake and exhaust. The stock adjusters were supposed to be used with them. I was always leary of using them because of the surfaces on the shaft. The push rod hole becomes a problem when you go to larger diameter push rods. I believe the problem would start with the 3/8" ones, 5/16" might make it.

I'm building up a Buick straight eight presently. After careful measurement the best ratio possible from the stock rocker is 1.51:1 when the adjuster ball is screwed nearly all the way up into the rocker. This is unuseable as the oiler holes no longer line up in this rather tenuous oiling setup to begin with. With the adjuster lowered to a more practical place in the rocker the ratio drops to 1.42:1.My solution was to physically relocate the rocker arm shaft .062 closer to the pushrods. I offset bored and rebushed the rocker arms and shaft stantions .062 towards the pushrod side of the engine.The net result is I now have a 1.66:1 rocker ratio, and no interference at the pushrod holes in the head. It cost me a week of spare time making the jigs to bore the rockers and stantions another week to do the machine work and about $80 worth of bushings and high temp bushing lock.